The long-term goal of this proposal is to provide a sound scientific basis on which to devise therapy regimens that can improve dental health of children and adolescents with oral health disparities. The objective of the current project is to examine the oral microbiota associated with dental caries in children, seeking differences that associate with and could explain increase d disease in children and adolescents, and differences in racial and socioeconomic groups in a population oral health disparities. A range of possible caries-associated species will be monitored including the mutans streptococci, several Actinomyces and Bifidobacterium, species, and selected periodontal pathogens. The first aim evaluates the microbiota of young children and adolescents using a DNA probe checkerboard assay. The association of microbial species with caries in different age, racial or ethnic, and socioeconomic groups, will be evaluated. The sequence of development of the oral microbiota in childhood may differ in children with and without disease. It is possible that poor oral health of adults with oral health disparities is based on, and could be predicted from the microbiota of childhood and adolescence. The second aim takes detection of caries out of the dental office into that of the pediatrician. A simple microbial sampling method will be evaluated for its ability to improve detection of early childhood caries. The third aim evaluates the microbiota of severe early childhood caries, the most prevalent oral infection in children that can impact children's general health. The aim evaluates whether comprehensive therapy changes the microbiota to that of caries-free children, and how the suppression of caries-associated species, including Streptococcus mutans, post-therapy, are associated with success of treatment. Information from this project should clarify the microbiota associated with childhood caries. OF clinical importance this project seeks ways facilitate improvement of dental health of under-served populations directed by evaluating improved diagnosis and risk assessment of childhood caries so effective therapy can be directed to children and adolescents most in need.